8.5.1.1 Development since the SAR

The model evaluation chapter of the IPCC Second Assessment Report (Gates et
al., 1996) found that “large-scale features of the current climate are
well simulated on average by current coupled models.” However, two major
points of concern were noted. Firstly, the SAR found that simulation of clouds
and related processes “remains a major source of uncertainty in atmospheric
models”. As discussed in Chapter 7, these processes
continue to account for most of the uncertainty in predicting human-induced
climate change. Secondly, the SAR noted an unsatisfactory situation involving
flux adjustments (Section 8.4.2): they “are relatively
large in the models that use them, but their absence affects the realism of
the control climate and the associated feedback processes”. Improvements
in coupled climate models since the SAR have addressed both points of concern.
For the atmospheric (as well as the oceanic) component, these improvements have
included higher horizontal resolution (which means less numerical diffusion
and better representation of topography), and advances in parametrizations.
In addition, the advent of the Coupled Model Intercomparison Program (CMIP;
see Meehl et al., 2000a) since the SAR has provided an additional database for
evaluating AOGCMs. Some basic details of models evaluated in this chapter and
used elsewhere in this report are presented in Table 8.1.

Table 8.1: Model control runs: a consolidated list
of coupled AOGCMs that are assessed in Chapter 8 and
used in other Chapters. The naming convention for the models is as agreed
by all modelling groups involved. Under the heading CMIP: 1,2 indicate that
the model control run is included in the Coupled Model Intercomparison Phase
1 and 2 (CMIP1 and 2) databases, respectively.

MODEL NAME

CENTRE

REFERENCE

CMIP

Ch 9

Ch 11

Ch 12

ATMOSPHERIC RESOLUTION

OCEAN RESOLUTION

LAND SURFACE

SEA ICE

FLUX ADJUST

1

ARPEGE/OPA1

CERFACS

Guilyardi and Madec, 1997

1

---

T21 (5.6 x 5.6) L30

2.0 x 2.0 L31*

C

(d)

-

2

ARPEGE/OPA2

CERFACS

Barthelet et al., 1998a,b

2

C--

T31 (3.9 x 3.9) L19

2.0 x 2.0 L31*

C

T

-

3

BMRCa

BMRC

Power et al., 1993

1

C--

R21 (3.2 x 5.6) L9

3.2 x 5.6 L12

M,B

T

-

4

BMRCb

BMRC

Power et al., 1998

2

---

R21 (3.2 x 5.6) L17

3.2 x 5.6 L12*

M,B

T

H,W

5

CCSR/NIES

CCSR/NIES

Emori et al., 1999

1,2

C-D

T21 (5.6 x 5.6) L20

2.8 x 2.8 L17

M,BB

T

H,W

6

CGCM1

CCCma

Boer et al., 2000;
Flato et al., 2000

1,2

C-D

*

*

T32 (3.8 x 3.8) L10

1.8 x 1.8 L29

M,BB

T

H,W

7

CGCM2

CCCma

Flato and Boer, 2001

-

-S-

*

*

T32 (3.8 x 3.8) L10

1.8 x 1.8 L29

M,BB

T,R

H,W

8

COLA1

COLA

Schneider et al., 1997;
Schneider and Zhu, 1998

1

---

R15 (4.5 x 7.5) L9

1.5 x 1.5 L20*

C

T

-

9

COLA2

COLA

Dewitt and Schneider, 1999

1

---

T30 (4 x 4) L18

3.0 x 3.0 L20*

C

T

-

10

CSIRO Mk2

CSIRO

Gordon and O’Farrell, 1997

1,2

C-D

R21 (3.2 x 5.6) L9

3.2 x 5.6 L21

C

T,R

H,W,M

11

CSM 1.0

NCAR

Boville and Gent, 1998

1,2

C--

T42 (2.8 x 2.8) L18

2.0 x 2.4 L45*

C

T,R

-

12

CSM 1.3

NCAR

Boville et al., 2001

-

-SD

T42 (2.8 x 2.8) L18

2.0 x 2.4 L45*

C

T,R

-

13

ECHAM1/LSG

DKRZ

Cubasch et al., 1992;
von Storch, 1994;
von Storch et al., 1997

1

---

*

T21 (5.6 x 5.6) L19

4.0 x 4.0 L11

C

T

H,W,M

14

ECHAM3/LSG

DKRZ

Cubasch et al 1997;
Voss et al., 1998

1,2

C-D

*

T21 (5.6 x 5.6) L19

4.0 x 4.0 L11

C

T

H,W,M

15

ECHAM4/OPYC3

DKRZ

Roeckner et al., 1996

1

C-D

*

*

T42 (2.8 x 2.8) L19

2.8 x 2.8 L11*

C

T,R

H,W(*)

16

GFDL_R15_a

GFDL

Manabe et al., 1991;
Manabe and Stouffer1996

1,2

C-D

*

R15 (4.5 x 7.5) L9

4.5 x 3.7 L12

B

T,F

H,W

17

GFDL_R15_b

GFDL

Dixon and Lanzante, 1999

-

C--

*

R15 (4.5 x 7.5) L9

4.5 x 3.7 L12

B

T,F

H,W

18

GFDL_R30_c

GFDL

Knutson et al., 1999

-

CS-

*

*

R30 (2.25 x 3.75) L14

1.875 x 2.25 L18

B

T,F

H,W

19

GISS1

GISS

Miller and Jiang, 1996

1

---

4.0 x 5.0 L9

4.0 x 5.0 L16

C

T

-

20

GISS2

GISS

Russell et al., 1995

1,2

C--

4.0 x 5.0 L9

4.0 x 5.0 L13

C

T

-

21

GOALS

IAP/LASG

Wu et al., 1997;
Zhang et al., 2000

1,2

C--

R15 (4.5 x 7.5) L9

4.0 x 5.0 L20

C

T

H,W,M

22

HadCM2

UKMO

Johns 1996;
Johns et al., 1997

1,2

C-D

*

2.5 x 3.75 L19

2.5 x 3.75 L20

C

T,F

H,W

23

HadCM3

UKMO

Gordon et al., 2000

2

CSD

*

2.5 x 3.75 L19

1.25 x 1.25 L20

C

T,F

-

24

IPSL-CM1

IPSL/LMD

Braconnot et al., 2000

1

---

5.6 x 3.8 L15

2.0 x 2.0 L31*

C

(d)

-

25

IPSL-CM2

IPSL/LMD

Laurent et al., 1998;

2

C--

5.6 x 3.8 L15

2.0 x 2.0 L31*

C

T

-

26

MRI1a

MRI

Tokioka et al., 1996

1,(2)a

C--

4.0 x 5.0 L15

2.0 x 2.5 L21(23)a*

M,B

T,F

H,W

27

MRI2

MRI

Yukimoto et al., 2000

-

CS-

*

T42(2.8 x 2.8) L30

2.0 x 2.5 L23*

C

T,F

H,W,M

28

NCAR1

NCAR

Meehl and Washington, 1995;
Washington and Meehl, 1996

1,2

---

R15 (4.5 x 7.5) L9

1.0 x 1.0 L20

B

T,R

-

29

NRL

NRL

Hogan and Li, 1997;
Li and Hogan, 1999

1,2

---

T47 (2.5 x 2.5) L18

1.0 x 2.0 L25*

BB

T(p)

H,W(*)

30

DOE PCM

NCAR

Washington et al., 2000

2

CSD

T42 (2.8 x 2.8) L18

0.67 x 0.67 L32

C

T,R

-

31

CCSR/NIES2

CCSR/NIES

Nozawa et al., 2000

-

CS-

T21 (5.6 x 5.6) L20

2.8 x 3.8 L17

M,BB

T

H,W

I1

BERN2D

PIUB

Stocker et al., 1992;
Schmittner & Stocker, 1999

-

---

*

10* x ZA L1

10* x ZA L15

-

T

-

I2

UVIC

UVIC

Fanning and Weaver, 1996;
Weaver et al., 1998

-

---

*

1.8 x 3.6 L1

1.8 x 3.6 L19

-

T,R

-

I3

CLIMBER

PIK

Petoukhov et al., 2000

-

---

*

10 x 51 L2

10 x ZA L11

C

T,F

-

a Model MRI1 exists in two versions. At the time of
writing, more complete assessment data was available for the earlier version,
whose control run is in the CMIP1 database. This model is used in Chapter
8. The model used in Chapter 9 has two extra
ocean levels and a modified ocean mixing scheme. Its control run is in
the CMIP2 database. The equilibrium climate sensitivities and Transient
Climate Responses (Chapter 9, Table
9.1) of the two models are the same.

CMIP: 1,2 indicate that the model control run is included in the
CMIP1 and CMIP2 databases, respectively.Ch 9: C indicates that a run or runs with the CMIP2 1% p.a. CO2
increase scenario is used in Chapter 9 (irrespective
of whether the data is included in the CMIP database). S indicates that
SRES scenario runs (including at least A2 and B2) are used in Chapter 9. D indicates that model output is lodged at the IPCC Data Distribution
Centre.Ch 11, Ch 12: An asterisk indicates that the model has been used
to make sea level projections (Chapter 11) or in
detection/attribution studies (Chapter 12).Atmospheric resolution: Horizontal and vertical resolution. The
former is expressed either as degrees latitude x longitude or as
a spectral trunca-tion with a rough translation to degrees latitude xlongitude.
An asterisk indicates enhanced meridional resolution in midlatitudes.
ZA indicates a zonally averaged model (360° zonal resolution). Vertical
resolution is expressed as “Lmm”, where mm is the number of
vertical levels.Ocean resolution: Horizontal and vertical resolution. The former
is expressed as degrees latitude xlongitude, while the latter is
expressed as “Lmm”, where mm is the number of vertical levels.
An asterisk indicates enhanced horizontal resolution near the Equator.
ZA indicates a zonally averaged model for each ocean basin. The following
classification of ocean horizontal resolution is used throughout Chapters
7 to 9: Coarse: >2°, Medium: 2/3°
to 2°, Eddy-permitting: 1/6° to 2/3°, Eddy-resolving: <1/6°.Land surface scheme: B = standard bucket hydrology scheme; BB =
modified bucket scheme with spatially varying soil moisture capacity and/or
a surface resistance; M = multi-layer temperature scheme; C = a complex
land surface scheme usually including multi-soil layers for temperature
and soil moisture, and an explicit representation of canopy processes.Sea ice model: T = thermodynamic ice model only; F = free
drift’ dynamics; R = ice rheology included; (d) = ice extent/thickness
determined diagnostically from ocean surface temperature; (p) = ice extent
prescribed.Flux adjustment: H = heat flux; W = fresh water flux; M = momentum
flux. An asterisk indicates annual mean flux adjustment only.